There was nothing original about the teacher's observations:
At Pasadena's Muir High School -- as on many urban campuses -- black students are cited more often than others for disciplinary problems. And they score worse than others on standardized exams.
What was shocking was how the white teacher argued -- when he connected the dots with his public proclamation -- that unruly black students were responsible for his school's failure to make the grade.
"It has absolutely nothing to do with teachers or curriculum," Scott Phelps wrote in a letter to fellow teachers at Muir, warning that test scores were likely to nose-dive. "Standards of behavior, or the lack thereof" are to blame.
He didn't hesitate to point the finger: "Overwhelmingly, the students whose behavior makes the hallways deafening, who yell out for the teacher and demand immediate attention in class, who cannot seem to stop chatting and are fascinated by each other but not with academics, in short, whose behavior saps the strength and energy of us on the front lines, are African American."
Now, a month later, that letter continues ricocheting around the country, bouncing off assumptions about race, youth and social class.
Phelps' letter resonated with many whites who feel threatened by the behavior of seemingly arrogant young black men. And it offended many blacks weary of being singled out for blame.
Those were the predictable reactions. Other responses were more nuanced, as the letter prompted finger-pointing, then soul-searching.
In newspaper columns, in private conversations, on talk radio, the "good" parents blamed the "bad" ones; teachers denounced other teachers.
At a forum in Pasadena, a teenager with bad grammar and a crude tattoo privately offered a thoughtful interpretation of her classmates' self-destructive attitudes, while a bookish college student said to alarmed adults: "I'm sorry, but no one listens to you."
And underneath their rancor and their hurt, many blacks felt an odd sort of gratitude.
At a neighborhood meeting about the letter, Kitty McKnight, a former teacher, exploded after a district official suggested that the solution to Muir's discipline problems was more tolerance and commitment from teachers.
"I cannot sit and listen to this!" she shouted, rising from her seat. "Our boys are out of control."
McKnight, who is black, graduated from Muir, sent her two now-grown sons there and recently retired after 40 years of teaching. "We have to do something," she told the crowd. "We are losing our boys!" There was scattered applause in the black audience, but many sat in stunned silence.
Later, McKnight admitted that Phelps' letter triggered feelings of anger and frustration, but also guilt.
"Having been a teacher all these years, I never made it a point. But it's true. You talk to another black teacher about the behavior of black students and they know exactly what you mean. I feel like I'm at fault for not addressing it sooner."
Others felt a sense of betrayal.
"I'm not saying it's true or not true," an angry father told a community meeting. "But it hurts to be held up to ridicule by someone whom we have entrusted our children's minds to."
It also hurts, Phelps said, to be labeled a racist for "simply making empirical observations of behavior that are totally supported by data."
Phelps left a research program at Caltech to teach high school science 12 years ago. He is known by peers as a passionate critic of district officials, and a hard-working, dedicated teacher. He tutors physics students for free, invites kids over for family dinners, visits their homes to host study sessions.
"He's not much of a public speaker or a disciplinarian, but he's one of the best teachers I ever had," said Muir alum Chad Hunter, who attends Pasadena City College and interns at Jet Propulsion Laboratory. It's a job he got with Phelps' help. "Mr. Phelps would do whatever it took to help, if you wanted to learn and you're willing to work."
Phelps says he never intended to insult black students. But many felt that his commentary, written in the dense style of an academic, had clear racial overtones. Black male teachers are better at controlling black students, he wrote, because they "have no trouble 'going off' on the kids."
In conversation, Phelps offers a list of white, Latino and Asian American teachers he says left Muir because they were intimidated by aggressive black students.
"The cultures are so different, in order for white teachers to feel comfortable they have to put a lot of energy into changing the behavior of kids who are not like them," he said.
It is Phelps' attribution of misbehavior to cultural deficiencies that really rankles his critics.
"If children are disruptive, let's say that. Let's not say they're disruptive because they're black," said Assistant Supt. George McKenna. "Some of these kids deserve credit just for showing up" at school, given their chaotic home lives and troubled neighborhoods.